Evaporation emission control device for fuel tanks

ABSTRACT

An evaporation control device consists of two spherical balls which float in a housing defining a cavity so that the balls move up and down in accordance with the fuel level in the tank to allow the top ball to engage a conical seat to seal the vented passageway from the fuel tank to the engine. The spherical contact surfaces between the two balls allow quick and easy movement of the top ball to seal the opening at once where gasoline moves toward the opening.

United States Patent Dragon et al.

[ 1 May 16, 1972 [54] EVAPORATION EMISSION CONTROL DEVICE FOR FUEL TANKS[72] Inventors: James W. Dragon, Arlington Heightst Alfred G. Ocken,Franklin Park, both of Ill.

[73] Assignee: Motorola, Inc., Franklin Park, Ill.

[22] Filed: Aug. 26, 1970 [2]] Appl. No.: 67,086

[52] US. Cl ..123/136, 137/202, 137/44 [51] Int. Cl ..Fl6k45/02,F16k3l/l8 [58] Field of Search 1 37/202, 430, 44; 123/ l 36;

[56] References Cited UNITED STATES PATENTS 3,500,843 3/1970 White..220/44 X 2,884,943 5/1959 Dobrick.....

..l37/202. 3,554,175 1/1971 Sarto. ..l23/l36 FOREIGN PATENTS ORAPPLICATIONS 506,788 9/1930 Germany ..l37/430 Primary Examiner-AlanCohan Attorney-Mueller & Aichele [57] ABSTRACT An evaporation controldevice consists of two spherical balls which float in a housing defininga cavity so that the balls move up and down in accordance with the fuellevel in the tank to allow the top ball to engage a conical seat to sealthe vented passageway from the fuel tank to the engine. The sphericalcontact surfaces between the two balls allow quick and easy movement ofthe top ball to seal the opening at once where gasoline moves toward theopening.

4 Claims, 2 Drawing Figures EVAPORATION EMISSION CONTROL DEVICE FOR FUELTANKS BACKGROUND OF THE INVENTION hydrocarbons from the automobileexhaust system, it has been noted that a substantial amount of pollutionis caused by evaporation of the gasoline used to supply power to theengine. That is, while driving an automobile substantially contributesto the pollution of our environment, it has been discovered that asubstantial amount of pollution will occur even if the automobiles arenot driven. The evaporation of the gasoline from the fuel tank as apollutant has been'investigated for the past several years and severalrather elaborate devices and arrangements have been utilized in anattempt to overcome the problem.

For example, one method of venting the fuel tank was by a directconnection of a conduit between the fuel tank and'the crankcase of theengine so that fuel vapor, together with oil vapor, can be withdrawnfrom the crankcase through the PCV valve of the engine into thecarburetor in the usual and wellknown manner. This direct fuelconnection presented problems in that, in some instances, raw fuel wouldbe drawn through this conduit connection. To eliminate the possibilityof ,raw fuel going through the conduit, an elaboratecontrol valveapparatus was devised which was relatively expensive and complicated.-

SUMMARY OF THE INVENTION Accordingly, it is an object of this inventionto provide an improved evaporation control valve for a fuel tank to openand close the conduit passageway from the fuel tank under certainselected conditions.

Another object of this invention is to provide an improved evaporationcontrol valve which is inexpensive to manufacture and efficient andreliable in operation.

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERREDEMBODIMENT Referring now to FIG. 1, an evaporation emission controldevice constructed in accordance with the principals of this inventionis designated generally by reference numeral 10 and is shown mounted tothe top wall 11 of a fuel tank 12. The evaporation emission controldevice 10 is shown in a conventional system where the fuel tank 12 holdsa quantity of gasoline 14 to supply fuel to a conventional internalcombustion reciprocating engine 16 through a fuel line 18. Interposed inthe fuel line 18 is a fuel pump 20 and a fuel filter 22 to pump gasolineand filter the same before it is delivered to a carburetor 24.

The evaporation emission control device 10 is in 'fluid communicationwith the crankcase area designated generally by reference numeral 16a,through a conduit 28. The evaporation emission control device 10 allowsgasoline vapor to escape from the fuel tank l2through the conduit 28 andinto the crankcase 1612 as long as the emission control device is in anopen valve condition. However, should the fuel tank 12 be completelyfilled with gasoline, or should an automobile containing the engine andfuel tank of FIG. I assume an angular attitude, going uphill ordownhill, where gasoline may pass through the conduit 28, theevaporation emission control device 10 automatically'and quickly willclose so that no gasoline or vapor will'pass through the conduit 28.When the automobile again assumes its normal attitude, the emissioncontrol device 10 will pass vapor to the crankcase area 16a once again.Gasoline vapor which enters the crankcase area 16a may be removed fromthe crankcase, together with oil vapor, through the standard PCV controlvalve 29in the usual and well-known'manner. However, it will beunderstood that the fuel vapor may be removed by any suitable means.

For a better understanding of the evaporation emissioncontrol device 10of this invention, reference is now made to FIG. 2 which illustrates anenlarged, partially sectional view of the device secured to the topwallportion of the fuel tank 12'. Here, the evaporation emission controldevice 10 includes threads 30 to which a fitting 30a can be attached sothat the conduit 28 can be connected thereto An opening 3lpasses throughthe threaded end 30 to. be in fluid communication with the conduit 28.The evaporation emission control device 10 may be fastened to the topwall 11 of the fuel tank 12 by solder or brazing it as indicated byreference numeral 32, or by any other suitable means of fastening. Theevaporation emission control device 10 has a housing portion 34extending into the fuel tank area, this housing portion beingillustrated herein as a cylindrical member with a foraminous wall 36 atone end thereof through which gaoline can flow easily. in theillustrated embodiment, the foraminous wall may be a screen which allowsgasoline freely to enter the cylindrical member when the fuel level ishigh'or when the automobile takes an angular attitude which tiltsorotherwise eausesfuel to come in contact with the device 10. A conicalseat 38'is formedat the uppermost end of the housing portion 34. Thisconical seat, together with the threaded portion 30 and the housingportion 34, may be an integral unit machined or cast in one piece, or itmay be several components fabricated together.

The evaporation emission control device 10 includes a first sphericalmember 40, which may or may not be floatable in the gasoline 14,arrangedto engage the conical seat 38' and close off the passageway 31 extendinginto the conduit 28. The spherical member 40 acts as a valve to controlopening and closing the passageway between the fuel tank 12 and thecrankcase 16a. A second spherical member 42, which is' floatable withinthe gasoline l4 and in any event floatable sufficient to support thefirst spherical member 40 fully above the fuel level, whether or not thefirst spherical member 40 is floatable in and of itself.

A point contract 44 between the two spherical members 40 and 42 providean almost frictionless support connection between these two balls sothat the first spherical member 40 will readily engage the conical seat38 under any angle of inclination from between 0 to 30 off the vertical.Therefore,

if the automobile is going uphill or downhill and gasoline tends toenter the conduit passageway 28 or as a result of gasoline movingrapidly from side-to-side or front-to-back because of acceleration orstopping of the automobile, the upper ball 40 will quickly engage theseat 38 to close off the conduit passageway 28 so no raw gasoline willpass to the crankcase.

By utilizing the double ball system, the upper ball 40 is completelyself-aligning with the seat 38 regardless of the rate at which gasolineis moved about in the tank. Also, since the ball 40 is free to rotate inany direction, the ball will not wear out in any given spot and, assuch, will last a long time re gardless of how often it engages the seat38. Also, it will be noted that no lubricant, other than gasolineitself, is needed.

What has been described is a simple and effective evaporation emissioncontrol device which prevents raw gasoline from entering the crankcaseof the engine when gasoline rises to the level of an openingcommunicating the fuel tank with the engine while allowing fortransmitting gasoline vapors from the fuel tank 12 to the engine 16.When utilizing the evaporation emission control device of thisinvention, it may be desirable to utilize a pressure cap 45 on thefiller neck 46 of the fuel tank 12.

Accordingly, it will be understood that variations and modifications ofthis invention may be effected without departing from the spirit andscope disclosed and claimed herein.

We claim:

1. A system for controlling the evaporation emissions from a fuel tankhaving a filler neck and a fuel line for delivering the fuel from thetank to the engine, including in combination, vent means including ahousing extending into the fuel tank, said housing defining a cavity andhaving a foraminous wall portion exposing the cavity to the interior ofthe fuel tank, conduit means connecting the housing to the engine fortransfer of volatile gas fumes thereto for disposal therein, ball seatmeans formed in a wall of said housing and having an opening connectingthe cavity thereof to said conduit means, a spherical valve memberpositioned in said housing and engageable with said ball seat means forsealing said conduit means, and float means positioned in said housingand having a spherical surface portion for engaging said spherical valvemember to move said spherical valve member into engagement with saidball seat means when said float means is elevated by the fuel levelwithin the fuel tank being tilted from a horizontal reference planethrough a plurality of angles up to at least 30 from said referenceplane.

2. The device of claim 1 wherein said housing is a cylindrical memberopen at one end thereof which extends into said fuel tank and saidforaminous wall is a screen which covers the open end of saidcylindrical member.

3. The device of claim 1 wherein said float means is a floatable ball.

4. The device of claim 1 wherein said housing is a cylindrical memberopen at one end and said foraminous wall is a screen covering said openend, said cylindircal member having a given diameter, said sphericalmember having a diameter greater than half the diameter of said givendiameter of said cylindrical member, and said float means has a diametergreater than one half the diameter of said cylindrical member.

1. A system for controlling the evaporation emissions from a fuel tankhaving a filler neck and a fuel line for delivering the fuel from thetank to the engine, including in combination, vent means including ahousing extending into the fuel tank, said housing defining a cavity andhaving a foraminous wall portion exposing the cavity to the interior ofthe fuel tank, conduit means connecting the housing to the engine fortransfer of volatile gas fumes thereto for disposal therein, ball seatmeans formed in a wall of said housing and having an opening connectingthe cavity thereof to said conduit means, a spherical valve memberpositioned in said housing and engageable with said ball seat means forsealing said conduit means, and float means positioned in said housingand having a spherical surface portion for engaging said spherical valvemember to move said spherical valve member into engagement with saidball seat means when said float means is elevated by the fuel levelwithin the fuel tank being tilted from a horizontal reference planethrough a plurality of angles up to at least 30* from said referenceplane.
 2. The device of claim 1 wherein said housing is a cylindricalmember open at one end thereof which extends into said fuel tank andsaid foraminous wall is a screen which covers the open end of saidcylindrical member.
 3. The device of claim 1 wherein said float means isa floatable ball.
 4. The device of claim 1 wherein said housing is acylindrical member open at one end and said foraminous wall is a screencovering said open end, said cylindircal member having a given diameter,said spherical member having a diameter greater than half the diameterof said given diameter of said cylindrical member, and said float meanshas a diameter greater than one half the diameter of said cylindricalmember.